1. Field of the Invention
The invention relates to a locking device, more particularly to a locking device for use in a bicycle brake system to retain a hand-operated brake lever of the brake system in a braked state.
2. Description of the Related Art
A bicycle used in either a circus or acrobatic performance includes a brake system with a hand-operated brake lever that can be retained at a braked state so that an acrobat can perform complex physical acts, such as somersaults and walking along the crossbar of the bicycle.
As illustrated in FIGS. 1, 2A, and 2B, a conventional locking device is shown together with a bicycle brake system 10 which includes a mounting seat 11 which is adapted to be fixed on a handlebar of the bicycle (not shown), and a hand-operated brake lever 12. A pivot 16 extends through holes formed through the first end 12A of the lever 12 and the seat 11, so that the second end 12B of the brake lever 12 can rotate about the pivot 16 in a clockwise direction upon actuation thereof in order to pull a brake cable 20 against the biasing action of the brake system 10, thereby achieving a braking effect. The conventional locking device includes a through hole unit which is formed through the seat 11 and which consists of a small-diameter hole section 112 and a large-diameter hole section 111, a locking bolt 13 inserted into the hole unit and prevented from disengaging from the seat 11 by means of a retainer ring 15 that is disposed in an annular groove of the small-diameter hole section 112, and a coil spring 14 sleeved around the locking bolt 13 so as to bias the latter in such a manner that the small-diameter section 131 of the locking bolt 13 is located in the hole unit while a portion of the large-diameter section 132 is exposed outwardly from the hole unit.
Referring to FIGS. 3A and 3B, when desired, the second end 12B of the lever 12 is pulled toward the handlebar of the bicycle (not shown) so as to rotate the same about the pivot 16 and correspondingly pulling the brake cable 20, thereby spacing a portion of the brake lever 12 adjacent to the first end 12A away from the seat 11. The locking bolt 13 is then pushed into the hole unit of the seat 11, wherein the large-diameter section 132 of the bolt 13 abuts against an abutment face 121 of the lever 12 so as to retain the latter in the braked state, i.e. retaining the lever 12 stationarily relative to the seat 11.
It is time-consuming to drill the hole unit through the seat 11 in order to mount the locking bolt 13 therein.